1. Field of the Disclosure
This disclosure generally relates to an optical apparatus and, more particularly, to an optical apparatus having the advantages of compact, low cost and easy fabrication.
2. Description of the Related Art
FIG. 1A show a schematic diagram of sensing the gesture movement by the conventional optical apparatus and FIG. 1B shows a cross-sectional view of the optical apparatus 100 of FIG. 1A. Please referring to FIGS. 1A and 1B together, the optical apparatus 100 includes a package housing 110, a light emitting device 120, a light sensitive device 130 and a condensing lens 140. The package housing 110 has a light outlet 112 and a light inlet 114, wherein a light beam L0 generated by the light emitting device 120 inside the package housing 110 ejects from the light outlet 112 and the light sensitive device 130 inside the package housing 110 is adapted to receive a light beam L1 reflected from a moving object 101 through the light inlet 114 so as to form an image. In addition, the condensing lens 140 is placed at the light inlet 114 and configured to collect the light beam L1 reflected by the moving object 101 and to image on the light sensitive device 130.
The traditional optical apparatus 100 mainly utilizes a single condensing lens 140 to image such that a total thickness of the optical apparatus 100 can not further be decreased. Generally speaking, it is possible to reduce the total thickness by adopting the Fresnel lens, but the total cost of the optical apparatus 100 can not be effectively reduced.